Objective 

Most prevalence studies of seasonal changes in mood and behavior have come from Western countries.

The authors'goal was to determine the prevalence ofseasonal changes in mood and behavior in a randomly selected group of Japanese workers.

Method 

They administered a Japanese translation of the Seasonal Pattern Assessment Questionnaire to 1,276 civil servants in Nagoya, Japan.

Results 

The estimated prevalence of winter seasonal affective disorder was 0.86%, the estimated prevalence of winter subsyndromal seasonal affective disorder was 0.86%, the estimated prevalence of summer seasonal affective disorder was 0.94%, and the estimated prevalence ofsummer subsyndromal seasonal affective disorder was 2.12%. Conclusions : The authors conclude that seasonal changes in mood and behavior occur in Japan, but at a lower frequency and with a different profile than in the United States or Europe.